Surfaced wallboard and the like



y 1941- I r c. c. HERITAGE I 2,248,233

SURFACED WALLBOARD AND THE LIKE 5 4 6mm 117x4 2")?? Patented June, 1941 sUaFAoEn WALLBOARD AND THE LIKE- Clark 0. Heritage, Cloqnet, Minn assignor to Wood Conversion Company, Cloquet, Minn, a,

corporation of Delaware Application September 10, 1938, Serial No. 229,253

1 Claim.

The present invention relates to an article of manufacture in the formof a surface coated sheet, such as heavy cardboard, wallboard, plywood, lumber and the like. 7

It is well known that many sheet materials are sumciently yieldable to havea tendency to warp, and that this is increased by a coating of paint, varnish, lacquer, or likematerial to one side of the sheet. These materials form a layer, film or skin, which on drying shrinks, and pulls the board with a force to produce warping.

The present invention provides a way of applying such materials to prevent such warping tendencies. It also aims to provide surfaceflnished wallboard free from the tendency to warp, and one which can be made flat and remain fiat.

Where the surface to be coated is a flat or smooth one, the invention requires that this surface be broken up into hills and valleys and like structures. This may be done by cutting into the sheet, or by adding material to the sheet. Then the hills and valleys are coated with the finishing substance; The hills and valleys provide for movement of the film, layer or coating to take up the contraction, and prevent the warping. These hills and valleys are comparable to the bows or loops put in long steam lines to take up the expansion and contraction. The hills and valleys are multiple applications of the same idea over an area rather than in a linear direction.

Another way in which the invention may be carried out is to provide a wallboard with decorative hills and valleys suitablydisposed to prevent warping forces in both rectangular dimensions. Such a board may be provided with an initial decorative surface, so that when a wall of it is finished with a coating composition which would otherwise cause warping forces, the board in the wall is safe from such warping tendency.

The invention may provide an irregular pattern, or a regular pattern.

The nature of the invention is better explained with reference to the accompanying drawing in which:

Fig. 1 represents a perspective view with cut end, of a piece of board embodying the invention.

Fig. 2 represents a plan viewof a board with a regular pattern of "waiiie iron type.

Fig. 3 is a cross-section of the board on line 3-3 of Fig. 2.

Fig. 4 is a side view of the piece of board of F 2.

Fig. 5 is a view like Fig. 1 of a modified type of marking in the board.

The numeral i0 designates a fiber insulation board of the type commonly installed for interior wall finish. This is mounted by causing the board to span supports, such as studs, rafters, 01 special furring strips. Warping of the board between supports is to be avoided. The application of pre-coated trim for wallboards has lead to a demand for precoated wallboard. The manufacturer of board therefore desires to apply paints, enamels, varnishes,- lacquers, resin coats, and the like to manufactured fiat sheets. Coated flat sheets of present day wallboard are relatively free from warping tendencies when stocked and when applied. But as soon as the manufacturer attempts to apply a finishing coating substance to the board, the sheet immediately acquires the tendency to warp. These may be maintained flat against warping by methods of stocking or packaging, but as soon as the individual sheets stand alone, the curvature appears.

By use of the present invention theabove problem has been solved. The invention requires a non-planar surface-for the board at the interface or boundary with the coating material. The coating need not be a well defined skin having a sharp interface with the board, and may be a ,thin layer of the board surface impregnated in part with the finishing material. It is the contour of the skin-layer or impregnated layer which determines its function in this invention.

The wallboard is preferably made originally with a surface to provide the desired contour.

' Therefore, in the manufacture of the fiber board frequently broken. Thus, the cross-section in any direction shows hills and valleys which effectively avoid a linear tension in the finishing ma terial i3.

In Figs. 2 to 4, a similar fiber board i5 originally lacking in proper hills and valleys is cut in crossing directions with two series of grooves i6 invention. A skin coat of finishing material is shown at l9.

In Fig. 5, a third form is shown which combines features of the other two forms. A single series' of grooves 20 is employed with reverse or S-curve formation. These give a contour of hills 2| and valleys 22 in every cross-section. The form shown is substantially sinusoidal, merely as an example. This form may be impressed in the board 23 as made or cut into a finished board. This design may be incorporated in part of a board and coupled with other designs in other parts. The finishing coat is designated 24.

Various modifications are contemplated as falling within the scope of the invention as defined by the appended claim.

I claim:

As an article of manufacture wallboard complied to warp the panel.

prising a yieldable fibrous panel formed substantially entirely of fibrous material, having an applied finishing coating material exposed at the surface thereof providing a continuous surface layer of the type tending normally to pull a fiatsurfaced coated board into awarped form, the finished surface of the board being irregular, being free from a planar area extending continuously across the surface of the panel, and being free from any continuous surface formed of parallel straight-line elements extending across the panel, a cross-section of the panel exhibiting an irregular contour line of hills and valleys at saidfinished surface, said hills and valleys tending to flatten and thereby providing satisfaction of the pulling force, whereby the force is not ap- CLARK C. HERITAGE. 

